My grandpa has an lt1 formula and he says its staring to give him trouble, I asked what was wrong and he said, When the car is cold its doing fine but when it warms up it starts (jerking and popping(in his words)and sometimes it will shut off. I personally changed out the thermostat and he changed out the cooling sensor, so what else could it be? thanks for the help

 

plugs and wires?

 

My guess is bad o2 sensor. The o2 sensors don't function util the car is warm and it goes into closed loop mode. That would explain why it doesn't do it when cold.

 

Is the check engine light on? If so, check the code. I would check everything mentioned above plus you could have a bad opti or maybe even a clogged fuel filter.

 

No its not throwing the check engine light on. whats the opti, is it expensive.

 

the spark distrubution system. kinda pricey its a real pos though.

 

do think that could be the problem

 

i dont think his opti is the problem. if it was the opti it would be missing all the time, not just when its warm. id go for the 02 sensors first.

how many miles are on the car?

 

This. Best way to check, take the car for a drive. When it warms up get on it hard. If the car accelerate flawlessly it's the primary O2 sensors going bad.

Often times when they go bad they don't throw codes because they're still performing "correctly" as far as the PCM is concerned. What happens is during light load they make small corrections in AFR for gas mileage reasons. When they go bad, they tell the car to run extremely rich. The car will cough sputter and pop a lot. However, when you go WOT the car overrides the O2 sensors and reads a more strict mapping from the PCM which means that the car will run like normal.

If there is another problem with the car going WOT will continue to pop, sputter etc in which I would look at the opti being the culprit.

 

so the "opti" is the the spark distribution system? sorry im still new to the ls1 world.

 

if the opti is the problem, ball park speaking, how much $$$ are we talking

 

I was reading a thread to a guys car that had a similiar promblem to mine but his car is an ls1, But i still throw it out there could it be the intake manifold gasket or a vacuum line from the pcv valve?

 

Could be a vac leak or something like that, they're not hard to test for but honestly what's been posted above is the most common solutions.

 

I think they are a little over 100 dollars and upwards from there for aftermarket ones.